1. Field of the Invention
The present invention relates to locks for portable containers and can be used, in particular, in containers intended for storing and transporting foodstuffs, medical preparations and chemical reagents, especially in the cases when spontaneous opening of these containers during their transportation should be avoided.
2. Description of the Prior Art
There is known a lock for a portable container having a body and a cover, comprising a lug to be fixed on the body of the container and a latch connected to this lug and having a hook-like end for engaging the cover of the container/cf. U.S. Pat. No. 2,872,066/. The latch is pressed against the cover of the container by a leaf spring fixed inside the container and engages with its hook-like end the flange of the cover.
For opening the container the latch is pulled outwardly to disengage its hook-like end and thereby release the cover. For closing the container the cover is positioned on the body thereof, in which case the cover presses with its flange on the hook-like end of the latch which in response moves outwardly and then under the action of the leaf spring engages the flange of the cover.
However, the construction of the above lock does not rule out spontaneous opening of the container, which may happen for different reasons including accidental mechanical action on the latch of the lock during transportation of the container. This is accounted for by the fact that the force pressing the latch to the cover of the container is not sufficient to hold it in place due to a relatively high ratio of the length of the latch arm between the latch end abutting against the body of the container and the hook-like end of the latch to the length of the latch arm between said end and the point whereto the pressing force of the spring is applied. Due to this the latch can be easily disengaged from the cover. For the same reason the latch at the place of its contact with the leaf spring is subjected to a high rate of wear.